Bus and rail commuters will be the first to see a series of posters that challenge their knowledge of physics.
They pose difficult questions such as: "How many planets the size of Earth would fit into the sun?" and "How many times would you have to cut the long side of a piece of A4 paper in half before it is the width of an atom?"
The Institute of Physics in association with the Government's Discover Science and Engineering programme have installed the posters in hundreds of buses on both sides of the border and on Dublin's commuter rail and bus systems.
The posters are also up in Waterford, Limerick, Cork and Galway, said Alison Hackett of the institute. And 200 buses in Northern Ireland are also carrying the series of physics teasers.
The scheme, "Transport yourself with Physics" was an Institute contribution to Science Week Ireland, now underway and running until Sunday next.
The questions include three multiple choice answers and each poster has a mobile number. If you text your answer -charged at the standard rate - you will either be congratulated for having the right answer or given the correct answer instantly.
"Physics is all about asking questions and being curious about the world around us," Ms Hackett said. "The posters grab people's attention before challenging their idea of physics."
The Institute also has a web site where people can check answers and try other questions, iopireland.org/questioncards
